FR2667361A1 - FUEL SUPPLY MANIFOLD WITH A VIBRATION DAMPING ACTION, FOR A FUEL SUPPLY LINE OF AN INTERNAL COMBUSTION ENGINE. - Google Patents

Abstract

The supply manifold essentially comprises a first tubular body (1) having a plurality of connectors (2) for metering and atomizing valves for fuel and a second tubular body (3) disposed in the first body and defining with this last a fuel supply pipe (4), the manifold also comprising a pressure regulator (7) to maintain a constant pressure in the fuel supply pipe; according to the invention, the second tubular body (3) is made of an elastically deformable material, so as to allow the shape and / or the volume of the fuel supply pipe (4) to vary, when the pressure prevailing in its breast varies sharply and sharply.

Description

-1 'Fuel supply manifold with a damping action of

  The present invention relates to a fuel supply manifold for a supply line of an internal combustion engine, which is arranged to supply fuel under pressure at a plurality of metering and fuel injection valves, electromagnetically actuated. Collectors of this type normally include a first tubular body which has a plurality of connectors for said valves and a second tubular body, disposed in the first body and defining with the latter a conduit for supplying fuel to the connectors, the conduit being limited by the interior and exterior surfaces of the first and second bodies

tubular respectively.

  Collectors of this type also include a pressure regulator serving to maintain the pressure of the fuel prevailing in the supply line, at a predetermined value. The regulator essentially comprises an inlet port and an outlet port for the fuel, which communicate respectively with the fuel supply duct and with the chamber located in the second tubular body, this chamber communicating with the exhaust The fuel is supplied to the supply duct, defined between the first and second tubular bodies, by the through an input connector; when the pressure prevailing in this conduit exceeds a predetermined value, a certain quantity of fuel is discharged through the pressure regulator to go into the chamber located in the second tubular body, and must be discharged towards the exhaust; for this purpose, the pressure regulator has a shut-off member which is arranged so as to allow the pressurized fuel to flow from the inlet port to the outlet port of the same regulator, when the pressure of the fuel prevailing in the pipe exceeds a predetermined value. The manifolds of this type, described briefly, also have the drawback that they do not allow the fuel to be supplied correctly to the metering and fuel injection valves, each time these valves are actuated so initiating the fuel injection phases in the respective cylinders, simultaneously, or when there are sharp and sudden pressure variations in the supply line going to the manifold In these cases, it has been found that the vibrations are triggered in the fuel contained in the manifold, with the consequence that the injection

  of fuel in the cylinders is irregular and not

  uniform. The object of the present invention is to provide a fuel supply manifold, of the type described briefly, which does not have the aforementioned drawback and which can thus allow fuel to be correctly supplied to the cylinders, even when the phases of injection of the metering and injection valves start at the same time and also when there are sharp and sharp pressure variations in the

  fuel contained in the supply pipe.

  This object is achieved by means of a fuel supply manifold for a fuel supply line of an internal combustion engine, serving to supply fuel under pressure to a plurality of metering valves and

  fuel injection, electro-operated

  magnetically, essentially comprising: a first tubular body having a plurality of connectors for the valves and a second tubular body, disposed in the first body and defining with the latter a supply duct, serving to supply fuel to the connectors, the duct being limited by the internal surface and the external surface of the first and second tubular bodies respectively, a pressure regulator for maintaining the pressure of the fuel prevailing in the supply line, at a predetermined value, the pressure regulator essentially comprising a port inlet and outlet for fuel, communicating respectively with the supply pipe and with the chamber located in the second tubular body, the latter communicating with the exhaust, characterized in that: the second tubular body is made of material elastically deformable, so as to allow the volume and / or the shape of the con fuel intake varies when it occurs within it sharp and brutal variations. For a better understanding of the structure of the intake manifold according to the invention, we will now

  provide a detailed description of the collector itself,

  made by way of example and with reference to the appended drawings, in which: FIG. 1 is a longitudinal section of a supply manifold according to the invention, and

  Figure 2 is an end view of the latter.

  Referring to the drawing, the supply manifold according to the invention essentially comprises a tubular body 1, for metering valves and

  fuel injection, electro-operated

  magnetically, known per se and therefore not shown The collector also comprises a second tubular body 3, disposed in the first body and defining with the latter a fuel supply duct 4, in communication with the connectors 2 and limited by the surface inner 5 and the surface

  outside 6 of the tubular bodies 1 and 3 respectively.

  A pressure regulator 7 is part of the manifold according to the invention and is arranged to maintain the fuel pressure, prevailing in the duct 4, at a predetermined value, this regulator essentially comprising an inlet port 8 and an outlet port 9 for fuel, which communicate respectively with the supply duct 4 and with the chamber 10 located in the second tubular body 3 The pressure regulator 7, which is known per se, essentially comprises a casing in which a shutter member is capable of moving, the member being arranged so as to allow passage between the inlet port 8 and the outlet port 9 normally closed, when the fuel pressure prevailing in the supply conduit 4 is less than a predetermined value and to open this passage when the pressure

exceeds said value.

  The pressure regulator 7 is suitably housed in a seat 13, formed in one end of the

first tubular body 1.

  One end of the second tubular body 3 is coupled to a connector 14 of the pressure regulator 7, in which the outlet orifice 9 opens, while the other end of the second tubular body 3 is coupled to a sleeve 15, in which is formed a discharge port 16, which communicates with a corresponding exhaust connector 17. Suitably, the sleeve 15 is housed in a socket 18, inserted in a cooperating seat 19 located in the other end of the first tubular body 1. In addition, the latter has an inlet connector 20 for supplying fuel to the supply duct, the sleeve 18 being suitably fixed to the tubular body 1 by means of a flange 21 provided with the arms 22, 23 and 24: the first of these arms having an opening in which the connector inlet 20 is inserted, the second having a cavity in which the connector 17 is inserted, while the third arm 24 surrounds the socket 18. According to the invention, the second tubular body 3 is made of elastically deformable material, so as to allow the volume and / or the shape of the fuel supply duct 4 to vary when variations occur

  brutal and clear pressure within it.

  Suitably, the material is a mixture of

  rubber, elastomer or thermoplastic resin.

  The collector described above works as below.

  below The fuel is brought under pressure to the supply duct 4, via the inlet connector 20, the fuel then being able to reach the metering and fuel injection valves via the corresponding connector 2 When the pressure prevailing in the supply line 4 exceeds a predetermined value, this produces an action on the pressure regulator 7, to cause the displacement of the shutter member, so as to open the passage of fuel between the supply line inlet 8 and outlet conduit 9: a certain amount of fuel can thus flow into chamber 10 located in the tubular body 3 and from this chamber, through orifice 16 and the

  output connector 17, to the exhaust.

  Although the pressure variations are abrupt and very large, such as those caused by the fuel supply pump, which supplies the fuel to the manifold, or each time the device is arranged so that the injection cycles for the metering and injection valves start at the same time, the tubular body 3 deforms elastically due to the deformation capacity of the material which constitutes it, the correct pressure being thus re-established in the supply duct 4 almost instantaneous and preventing the triggering of vibrations in the fuel itself Thus, the second tubular body 3, as well as allowing the fuel to be discharged from the pressure regulator 7 to the exhaust connector 17, also functions effectively to dampen the vibrations and adjust the pressure: this action being due to the elastic deformation of the wall of the tubular body 3, a

  deformation which occurs substantially radially.

  It is of course possible to make modifications and variations of the embodiment described, of the present invention, both in the form and in the arrangement of the different parts, without thereby departing from the scope of

the invention itself.

Claims (4)

RESELL ICAT IONS   1 Fuel supply manifold for a fuel supply line of an internal combustion engine, serving to supply fuel under pressure to a plurality of metering and fuel atomization valves, electromagnetically actuated essentially comprising : a first tubular body (1) having a plurality of connectors (2) for the valves and a second tubular body (3), disposed in the first body and defining therewith a supply duct, serving to supply fuel to the connectors, the conduit being limited by the inner surface (5) and the outer surface (6) of the first and second tubular bodies respectively, a pressure regulator (7) for maintaining the pressure of the fuel prevailing in the intake conduit (4 ), at a predetermined value, the pressure regulator essentially comprising an inlet port (8) and an outlet port (9) for the fuel, communicating respectively nt with the supply duct (4) and with the chamber (10) located in the second tubular body (3), the latter communicating with the exhaust, characterized in that: the second tubular body (3) is made of elastically deformable material, so as to allow the volume and / or the shape of the fuel supply duct (4) to vary when it occurs within it clearly and brutal variations.   2 collector according to claim 1, characterized in that the second tubular body (3) is manufactured in one rubber compound.   3 collector according to claim 1, characterized in that the second tubular body (3) is made of elastomer. 4 collector according to claim 1, characterized in that the second tubular body (3) is manufactured in thermoplastic resin.   Collector according to any one of the claims   previous, characterized in that the pressure regulator (7) is housed in a seat (13), formed in one end of the first tubular body (1), a connector (14) of the pressure regulator (7), which is formed with the unloading orifice (9), being installed in the first end of the second tubular body (3), the second end of which houses a socket (15) fixed to the other   end of the first tubular body (1).   6 collector according to claim 5, characterized in that the sleeve (15) is housed in a sleeve (18) fixed   at said other end of the first tubular body (1).